Propylene polymer compositions

Abstract: A propylene polymer composition comprising (a) a propylene polymer (b) an olefin type elastomer and (c) a polar group-containing olefin polymer composition obtained by heating (c-1) an olefin polymer containing a carboxyl group or an acid anhydrous group in its molecule and (c-2) an amino compound, or comprising (a) a propylene polymer, (b) an olefin type elastomer, (c-1) an olefin polymer containing a carboxyl group or an acid anhydrous group in its molecule and (c-2) an amino compound. The propylene polymer compositions are particularly compatible with urethane or amino-coatings.

Description: The present invention relates to propylene polymer compositions having excellent properties of being coated (i.e., having excellent coating adhesion), and more particularly to propylene polymer compositions which have high adhesion to coatings such as melamine resin coatings and urethane resin coatings even if the compositions are not subjected to any surface treatment with, for example, a primer or a solvent. Propylene polymers have been widely prepared on an industrial scale because they have excellent properties such as mechanical properties, heat resistance, solvent resistance, oil resistance and chemical resistance. Propylene polymers having such properties are widely used as materials for industrial parts, e.g. automotive parts and electrical apparatus parts, and daily necessities. The propylene polymers are chemically inert and safe because they have no polar groups in their molecules. However, because they have no polar groups, they have poor adhesion to other resins. Therefore, for coating a molded product formed from the propylene polymer with, for example, a urethane resin coating, it is necessary to perform a treatment to improve the affinity of the surface of the product for the resin coating, such as an electrical treatment (e.g., corona discharge), mechanical surface-roughening treatment, flame treatment, oxygen treatment or ozone treatment. Prior to practicing these surface treatments, the surface of the molded product is generally cleaned, with a solvent such as an alcohol or aromatic hydrocarbon or with the vapors of a solvent such as trichloroethylene, perchloroethylene, pentachloroethylene or toluene. An apparatus is necessary to conduct the above-mentioned surface treatments, but this is economically disadvantageous. In addition these treatments require a long period of time. Other than the method of the pretreatment of the molded product, also utilized is a method of coating the molded product with a primer which is able to adhere to propylene polymers and then applying a coating such as a urethane resin coating to the surface of the primer layer. In this method, however, two steps comprising the primer coating (undercoating) and the topcoating (final coating) are necessary, and hence this method also needs a long period of time for the coating. Further, formation of the two-layer structure consisting of the primer layer and the topcoating layer on the molded product increases costs. With regard to the coating of molded products formed from the propylene polymers, the molded products are generally subjected to a treatment as described above. In other words, the molded products formed from the conventionally known propylene polymers must be subjected to a pretreatment prior to the coating. Accordingly, propylene polymers which do not need such pretreatments as described above and which have excellent adhesion of coatings have been desired for a long time. The present invention seeks to overcome the above-mentioned problems of propylene resin compositions and to provide propylene polymer compositions having excellent adhesion to various coatings such as melamine resin coatings and urethane resin coatings. EP-A-336,780 discloses a thermoplastic resin or elastomer composition which is formed by blending under heating 100 parts by weight of a thermoplastic resin or elastomer obtained by dynamically heat-treating a blend of (a) a peroxide-crosslinkable olefin type copolymer and/or (b) an olefin type plastic [the sum of the components (a) and (b) is 100 parts by weight] and (c) 0.01 to 10 parts by weight of an unsaturated carboxylic acid or a derivative thereof in the presence of an organic peroxide, with (d) 0.01 to 10 parts by weight of a monomer containing at lest one amino group. EP-A-525,585 discloses a composition comprising an olefin resin, a copolymer of an «-olefin and a non-conjugated diene, and a polymer selected from, inter alia, polymers containing a carboxyl group and polymers containing an amino group. The present invention provides a first propylene polymer composition comprising: (a) a propylene polymer in an amount of 1 to 99 parts by weight, (b) an olefinic elastomer having a Mooney viscosity ML 1+4 (100°C) of 10 to 150 in an amount of 99 to 1 parts by weight, the total amount of components (a) and (b) being 100 parts by weight, and (c) a polar group-containing olefin polymer in an amount from 1 to 30 by weight based on the total weight of components (a) and (b), said polymer (c) being obtainable by heating (c-1) an olefin polymer comprising carboxyl group and/or acid anhydride groups and (c-2) an amino compound. The present invention also provides a second propylene polymer composition comprising: (a) a propylene polymer in an amount of 1 to 99 parts by weight, (b) an olefinic elastomer having a Mooney viscosity ML 1+4 (100°C) of 10 to 150 in an amount of 99 to 1 parts by weight, the total amount of components (a) and (b) being 100 parts by weight, (c-1) an olefin polymer comprising carboxyl group and/or acid anhydride groups in an amount from 1 to 20% of the total weight of components (a) and (b), and (c-2) an amino compound which is capable of reacting with the olefin polymer (c-1) in an amount from 0.01 to 10% of the total weight of components (a) and (b). The propylene polymer (a) is a homopolymer of propylene or a copolymer of propylene with another α-olefin. Examples of the α-olefin copolymerizable with propylene include ethylene, 1-butene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene, 1-heptene, 1-methylhexene, 4-methyl-1-pentene, 1-trimethylbutene, 1-ethylpentene, 1-octene, 1-methylpentene, 1-dimethylhexene, 1-trimethylpentene, 1-ethylhexene, 1-methylethylpentene, 1-diethylbutene, 1-propylpentene, 1-decene, 1-methylnonene, dimethyloctene, 1-trimethylheptene, 1-ethyloctene, 1-methylethylheptene, 1-diethylhexene, 1-dodecene and hexadodecene. These α-olefins may form random copolymers or block copolymers with the propylene. In the present invention, preferred are a propylene homopolymer, a crystalline propylene/ethylene block copolymer having an ethylene content of 2 to 40 % by mol, and a crystalline propylene/ethylene random copolymer having an ethylene content of 0.5 to 10 % by mol. The propylene polymer (a) has a melt flow rate (MFR, measured in accordance with ASTM D 1238 at 230 °C under a load of 2.16 kg) of 0.05 to 200 g/10 min, preferably 0.05 to 100 g/10min, more preferably 0.5 to 60 g/10 min. By the use of the propylene polymer having such an MFR, excellent moldability can be assured. It is desired that the density of the propylene polymer (a) is usually from 0.89 to 0.92 g/cm 3 . The propylene polymer (a) can be prepared by various processes. In one typical process, the propylene polymer (a) can be prepared in the presence of a catalyst formed from a solid titanium catalyst component and an organometallic compound catalyst component or in the presence of a catalyst formed from the above two components and an electron donor. The solid titanium catalyst component is titanium tetrachloride or a titanium tetrachloride composition prepared by various processes and is supported on a carrier preferably having a specific surface area of not less than 100 m 2 /g, or a titanium catalyst component which contains as its essential components magnesium, a halogen, an electron donor (preferably an aromatic carboxylic ester or alkyl group-containing ether) and titanium and which is supported on a carrier preferably having a specific surface area of not less than 100 m 2 /g. A propylene polymer prepared using the latter carrier type catalyst component is preferred. The organometallic compound catalyst component is preferably an organoaluminium compound. Examples of the organoaluminium compound include a trialkylaluminium, dialkylaluminium halide, alkylaluminium sesquihalide and alkylaluminium dihalide. The organoaluminium compound can be appropriately selected according to the kind of the titanium catalyst component used. Employable as the electron donor is an organic compound containing an oxygen atom, a nitrogen atom, a phosphorus atom, a sulfur atom, a silicon atom or a boron atom. Preferred electron donors include ester and ether compounds containing these atoms. Processes for preparing propylene polymers using the above-described carrier type catalyst components are disclosed in detail, for example, in JP-A-108385/1975 JP-A-126590/1975, JP-A-20297/1976, JP-A-28189/1976 and JP-A-151691/1977. The techniques described in these publications can be also applied to the present invention. The propylene polymer (a) is used in an amount of 1 to 99 parts by weight, preferably 20 to 95 parts by weight, more preferably 30 to 80 parts by weight, based on 100 parts by weight of the total amount of the propylene polymer (a) and the olefinic elastomer (b). The olefinic elastomer (b) is a copolymer of an α-olefin such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene or 1-octene, or a copolymer of such an α-olefin with a non-conjugated diene. Examples of the non-conjugated diene include dicyclopentadiene, 1,4-hexadiene, dicyclooctadiene, methylenenorbornene and 5-ethylidene-2-norbornene. Examples of the olefinic elastomer (b) include amorphous elastomeric copolymers derived from olefins, such as ethylene/propylene copolymer rubber, ethylene/1-butene copolymer rubber, ethylene/propylene/1-butene copolymer rubber, ethylene/propylene/non-conjugated diene copolymer rubber, ethylene/1-butene/non-conjugated diene rubber and ethylene/propylene/1-butene/non-conjugated diene copolymer rubber. The olefinic elastomer (b) has a Mooney viscosity [ML 1+4 (100°C), JIS K 6300] of 10 to 150, preferably 40 to 120. The iodine value (degree of unsaturation) of the olefinic elastomer (b) is preferably 16 or less. The olefinic elastomer (b) is used in an amount of 99 to 1 parts by weight, preferably 80 to 5 parts by weight, more preferably 70 to 20 parts by weight, based on 100 parts by weight of the total amount of the propylene polymer (a) and the olefinic elastomer (b). The polar group-containing olefin polymer (c) used in the first propylene polymer composition of the present invention is obtainable by heating (c-1) an olefin polymer comprising carboxyl and/or acid anhydride groups and (c-2) an amino compound. Examples of the olefin polymer (c-1) are: (1) a copolymer of an α-olefin with an unsaturated compound containing a carboxyl group or an acid anhydride group; (2) a copolymer obtained by grafting an unsaturated compound containing a carboxyl group or an acid anhydride group to a homopolymer or copolymer of an α-olefin; and (3) a copolymer obtained by grafting an unsaturated compound containing a carboxyl group or an acid anhydride group to a copolymer of an α-olefin with an unsaturated compound containing a carboxyl group or an acid anhydride group. The above olefin polymers (1) to (3) are now described in more detail. Examples of the α-olefins used for the above olefin polymer (1) include the same α-olefins as enumerated before with respect to the propylene polymer (a), which are copolymerizable with propylene. Examples of the unsaturated compound containing a carboxyl group or an acid anhydride group, which is used for the above olefin polymer (1), include α, β-unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid and methyltetrahydrophthalic acid; α, β-unsaturated carboxylic anhydrides, such as maleic anhydride, itaconic anhydride, citraconic anhydride and tetrahydrophthalic anhydride; and unsaturated carboxylic anhydrides, such as bicyclo[2.2.l]hepto-2-ene-5,6-dicarboxylic anhydride. Of these, preferred are acrylic acid, maleic acid, itaconic acid, maleic anhydride and itaconic anhydride. In the olefin polymer (1), the molar ratio of the unsaturated compound the α-olefin (unsaturated compound: α-olefin) is 3:97 to 40:60, preferably 5:95 to 35:65. The olefin polymer (1) can be prepared by, for example, a conventionally known process such as high-pressure radical polymerization. In the preparation of the olefin polymer (1) by high-pressure radical polymerization, the above-mentioned unsaturated compound is copolymerized with an α-olefin in the presence of a radical initiator in an reaction vessel kept at a pressure of 1,000 to 3,000 atm (101 to 304 MPa) and at a temperature of 90 to 300 °C. The olefin polymer (1) prepared by the above process contains the carboxyl group or the acid anhydride group in an amount of 0.01 to 50 % by weight, preferably 0.05 to 10 % by weight, per 100 % by weight of the olefin polymer (1). There is no specific limitation on the intrinsic viscosity of the olefin polymer (1) as prepared by the above process, but the olefin polymer (1) preferably has a low-molecular weight from the viewpoint of dispersibility in the propylene polymer composition. The intrinsic viscosity of the olefin polymer (1) as measured in decalin at 135 °C is preferably 0.1 to 2.0 dl/g, more preferably 0.1 to 1.0 dl/g, most preferably 0.15 to 0.8 dl/g, particularly preferably 0.2 to 0.5 dl/g. When the olefin polymer (1) has the intrinsic viscosity mentioned above, propylene polymer compositions can be easily prepared and the propylene polymer compositions thus prepared have excellent mechanical properties and excellent adhesion properties to coatings such as urethane resin coatings. The homopolymer or copolymer of an α-olefin used for the olefin polymer (2) includes the polymers described before with respect to the propylene polymer (a) and the olefin type elastomer (b). Examples include propylene homopolymer, propylene/ethylene block copolymer, propylene/ethylene random copolymer, ethylene/propylene copolymer rubber, ethylene/1-butene copolymer rubber, ethylene/propylene/1-butene copolymer rubber, ethylene/propylene/non-conjugated diene copolymer rubber, ethylene/1-butene/non-conjugated diene copolymer rubber and ethylene/propylene/1-butene/non-conjugated diene copolymer rubber. Also employable as the homopolymer of an α-olefin are high-density polyethylene, high-pressure low-density polyethylene, linear low-density polyethylene, poly-1-butene and poly-4-methyl-1-pentene. Of these, preferred are a propylene homopolymer and a crystalline propylene/ethylene random copolymer having an ethylene content of 0 to 10 % by mol, preferably 1 to 5 % by mol, from the viewpoints of rigidity and adhesion of the coating. Examples of the unsaturated compound containing a carboxyl group or an acid anhydrous group, which is used for the olefin polymer (2), are the same as those used for the aforesaid olefin polymer (1). Examples of the copolymer of an α-olefin with the unsaturated compound, which is used for the olefin polymer (3), include ethylene/acrylic acid copolymer, ethylene/methacrylic acid copolymer, ethylene/vinyl acetate copolymer, ethylene/vinyl alcohol copolymer, ethylene/ethyl acrylate copolymer and ethylene/maleic anhydride copolymer. Examples of the unsaturated compound containing a carboxyl group or an acid anhydride group, which is used for the olefin polymer (3), are the same as those used for the aforesaid olefin polymer (1). The olefin polymers (2) and (3) can be obtained by heating the α-olefin homopolymer, the α-olefin copolymer, the α-olefin polymer (e.g., a copolymer of an α-olefin and the unsaturated compound) and the unsaturated compound containing a carboxyl group or an acid anhydride group in the presence of a radical initiator to perform a graft reaction. As the radical initiator, compounds such as organic peroxides and azo compounds are employable. Examples of the organic peroxides include: peroxy ketals, such as 1,1-bis(t-butylperoxy)-3,5,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(t-butylperoxy)octane, n-butyl-4,4-bis(t-butylperoxy)valerate and 2,2-bis(t-butylperoxy)butane; dialkyl peroxides, such as di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane and 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3; diacyl peroxides, such as acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide and m-toluoyl peroxide; peroxy esters, such as t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butylperoxy-2-ethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, di-t-butyl peroxyisophthalate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butylperoxymaleic acid, t-butyl peroxyisopropylcarbonate and cumyl peroxyoctate; and hydroperoxides, such as t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide and 1,1,3,3-tetramethylbutyl hydroperoxide. Of these, preferred are 1,1-bis(t-butylperoxy)-3,5,5-trimethylcyclohexane, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m-toluoyl peroxide and t-butylperoxy-2-ethylhexanoate. The azo compound is, for example, azoisobutyronitrile. The above-exemplified radical initiators can be used singly or in combination. The unsaturated compound containing a carboxyl group or an acid anhydride group is used in an amount of 0.01 to 50 parts by weight, preferably 0.1 to 40 parts by weight, based on 100 parts by weight of the α-olefin polymer. The radical initiator is used in an amount of 0.01 to 10 parts by weight, preferably 0.05 to 8 parts by weight, based on 100 parts by weight of the α-olefin polymer. The graft modification can be carried out by conventionally known processes, for example, by the following processes: (i) Melt-kneading the α-olefin polymer and the unsaturated compound containing a carboxyl group or an acid anhydride group in the presence of the radical initiator by a kneading apparatus such as an intensive mixer or an extruder. This kneading is preferably carried out in an atmosphere of an inert gas such as nitrogen. The kneading temperature used is a temperature such that the half-life of the radical initiator used becomes 1 minute generally the temperature is 150 to 280 °C, preferably 170 to 240 °C, and the kneading time is usually 30 seconds to 20 minutes, preferably 1 to 10 minutes. (ii) Adding the unsaturated compound containing a carboxyl group or an acid anhydride group and the radical initiator to the α-olefin polymer in the molten state with stirring to mix them with each other. This stirring is preferably carried out in an atmosphere of an inert gas such as nitrogen. The stirring temperature used is a temperature such that the half-life of the radical initiator used becomes 1 minute. The temperatur is generally 150 to 280 °C, preferably 170 to 240 °C. The mixing time is usually 0.5 to 10 hours, preferably 1 to 5 hours. The unsaturated compound containing a carboxyl group or an acid anhydride group and the radical initiator may be added together during the melting procedure of the α-olefin polymer, or may be dropwise added separately to the molten α-olefin polymer. (iii) Adding the unsaturated compound containing a carboxyl group or an acid anhydride and the radical initiator to an organic solvent solution of the α-olefin polymer and heating them. This heating is preferably carried out in an atmosphere of an inert gas such as nitrogen. The heating temperature used is a temperature such that the half-life of the radical initiator used becomes 1 minute. The temperature is generally 100 to 200 °C, preferably 120 to 180 °C, and the heating time is usually 0.5 to 10 hours, preferably 1 to 5 hours. The unsaturated compound containing a carboxyl group or an acid anhydride group and the radical initiator may be added together when the α-olefin polymer is dissolved in the organic solvent, or may be dropwise added separately to the organic solvent solution of the α-olefin polymer. Employable as the organic solvent are aromatic hydrocarbons such as benzene, toluene and xylene; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and chlorine type hydrocarbons such as chlorobenzene and dichlorobenzene. (iv) Adding the unsaturated compound containing a carboxyl group or an acid anhydride group and the radical initiator to an aqueous dispersion of the α-olefin polymer and heating them. This heating is preferably carried out in an atmosphere of an inert gas such as nitrogen. The heating temperature used is usually 60 to 150 °C, preferably 80 to 100 °C, and the heating time is usually 0.5 to 10 hours, preferably 1 to 5 hours. The unsaturated compound containing a carboxyl group or an acid anhydride group and the radical initiator may be added together when the α-olefin polymer is dispersed in water, or may be dropwise added separately to the aqueous dispersion of the α-olefin polymer. Other than the above-exemplified radical initiators, water-soluble persulfates such as potassium persulfate and ammonium persulfate are also employable as the radical initiator. (v) Heating the α-olefin polymer and the unsaturated compound containing a carboxyl group or an acid anhydride group in the presence of the radical initiator at a temperature of not higher than the melting point of the α-olefin polymer, for example, not higher than 165 °C in the case of a propylene polymer, or not higher than 140 °C in the case of an ethylene polymer. This heating is preferably carried out in an atmosphere of an inert gas such as nitrogen. The heating time is usually 0.5 to 10 hours, preferably 1 to 5 hours. The unsaturated compound containing a carboxyl group or an acid anhydride group and the radical initiator may be added together when the α-olefin polymer is heated, or may be dropwise added separately to the already heated α-olefin polymer. Of the above-mentioned modification processes, preferred are processes (ii) and (iii) in which the graft amount can be easily made large and modified olefin polymers having an intrinsic viscosity, as measured in decalin at 135 °C, of not more than 1.0 dl/g can be easily prepared. In the olefin polymer (2) or (3) prepared by the above process, the carboxyl group or the acid anhydride group is present in an amount of 0.01 to 50 % by weight, preferably 0.05 to 10 % by weight, per 100 % by weight of the olefin polymer (2) or (3). There is no specific limitation on the intrinsic viscosity of the olefin polymer (2) or (3) as prepared in the above processes, but these olefin polymers preferably have a low-molecular weight from the viewpoint of dispersibility in the propylene polymer composition. The intrinsic viscosity of the olefin polymer (2) or (3) as measured in decalin at 135 °C is preferably 0.1 to 2.0 dl/g, more preferably 0.1 to 1.0 dl/g, most preferably 0.15 to 0.8 dl/g, particularly preferably 0.2 to 0.5 dl/g. When the olefin polymer (2) or (3) has the intrinsic viscosity mentioned above, propylene polymer compositions can be easily prepared and the propylene polymer compositions thus prepared have excellent mechanical properties and excellent adhesion properties to coatings such as urethane resin coatings. The preferred olefin polymer (c-1) is a propylene homopolymer which contains a carboxyl group or an acid anhydride group, or a propylene/ethylene random copolymer which has an ethylene content of 1 to 5 % by mol and contains a carboxyl group or an acid anhydride group. A particularly preferred propylene/ethylene random copolymer has an ethylene content of 1 to 5 % by mol and an intrinsic viscosity [η], as measured in decalin at 135 °C, of 0.1 to 1.0 dl/g and contains a carboxyl group or an acid anhydride. The amino compound (c-2) is a compound having at least one amino group. Examples of the amino compound include: amino alcohols, such as 2-aminoethanol, 3-amino-1-propanol; 4-amino-1-butanol, 5-amino-1-pentanol, 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol, N-aminoethylethanolamine and 2-(2-aminoethoxy)ethanol; diamines, such as ethylenediamine, propylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine and hexamethylenediamine; polyamines, such as diethylenetriamine, triethylenetetramine and tetraethylenepentamine; dicarboxylic acid amides, such as oxamide, malonamide, succinamide, adipamide, malamide and d-tartaramide. hydrazines, such as methylhydrazine and ethylhydrazine; and aromatic amines, such as phenylenediamine, toluenediamine, N-methyldiamine, N-methylphenyldiamine and aminodiphenylamine. Of these, 2-aminoethanol, N-aminoethylethanolamine and 2-(2-aminoethoxy)ethanol are particularly preferred. The polar group-containing olefin polymer (c) can be obtained by heating the olefin polymer (c-1) and the amino compound (c-2), as described above. The amino compound (c-2) is generally used in an amount of 0.3 to 100 times, preferably 0.5 to 50 times, more preferably 1 to 20 times, the number of moles of the carboxyl group or the acid anhydride group contained in the olefin polymer (c-1). The heating of both components is carried out, for example, by the following processes: (I) Melt-kneading the olefin polymer (c-1) and the amino compound (c-2); (II) Dissolving the olefin polymer (c-1) and the amino compound (c-2) in an organic solvent and heating the resulting solution; (III) Dispersing the olefin polymer (c-1) and the amino compound (c-2) in an aqueous medium and heating the resulting aqueous dispersion; and (IV) Heating the olefin polymer (c-1) and the amino compound (c-2) at a temperature of not lower than the melting point of the olefin polymer (c-1). There is no specific limitation on the intrinsic viscosity of the polar group-containing olefin polymer (c) prepared by the above processes, but the polar group-containing olefin polymer (c) preferably has a low-molecular weight from the viewpoint of dispersibility in the propylene polymer composition. The intrinsic viscosity of the polar group-containing olefin polymer (c) as measured in decalin at 135 °C is preferably 0.1 to 2.0 dl/g, more preferably 0.1 to 1.0 dl/g, most preferably 0.15 to 0.8 dl/g, particularly preferably 0.2 to 0.5 dl/g. The reaction ratio between the olefin polymer (c-1) and the amino compound (c-2) is generally 30 to 100 %, preferably 50 to 100 %, more preferably 80 to 100 %, in terms of the reaction ratio based on the carboxyl group or the acid anhydride group contained in the olefin polymer (c-1). After the polar group-containing olefin polymer composition (c) is prepared as above, if necessary the unreacted amino compound (c-2) may be removed to purify the composition (c). The purification is carried out, for example, by the following methods: (X) Melting the polar-group containing olefin polymer (c) by heating and then exposing the molten olefin polymer (c) to a high vacuum to evaporate the unreacted amino compound (c-2) so as to remove it; (Y) Dissolving the polar-group containing olefin polymer (c) in an organic solvent, then introducing the resulting solution into a poor solvent for the olefin polymer (c-1) and separating the liquid phase by filtration; and (Z) Washing a powder of the polar group-containing olefin polymer (c) with a poor solvent for the olefin polymer (c-1). Even if the polar group-containing olefin polymer (c) contains the unreacted amino compound (c-2), it can be employed for the preparation of the propylene polymer composition of the present invention, so long as the object of the invention is not marred. In the first·propylene polymer composition of the present invention, the polar group-containing olefin polymer (c) is used in an amount of 1 to 30 % weight, preferably 1 to 10 % by weight, more preferably 2 to 7 % by weight, based on the total weight of the propylene polymer (a) and the olefin type elastomer (b). In the second propylene polymer composition of the present invention, to the propylene polymer (a) and the olefinic elastomer (b) are added the olefin polymer (c-1) containing a carboxyl group or an acid anhydride group and the amino compound (c-2). In this case, the olefin polymer (c-1) is used in an amount of 1 to 20 % by weight, preferably 2 to 10 % by weight, more preferably 3 to 7 % by weight, based on the total weight of the propylene polymer (a) and the olefinic elastomer (b); and the amino compound (c-2) is used in an amount of 0.01 to 10 % by weight, preferably 0.05 to 7 % by weight, more preferably 0.1 to 5 % by weight, based on the total weight of the propylene polymer (a) and the olefinic elastomer (b). The first propylene polymer composition according to the invention is prepared by melt-kneading 1 to 99 parts by weight of the propylene polymer (a), 99 to 1 part by weight of the olefinic elastomer (b), [the total amount of components (a) and (b) being 100 parts by weight], and 1 to 30 parts by weight of the polar group-containing olefin polymer composition (c). The second propylene polymer composition according to the invention is prepared by melt-kneading 1 to 99 parts by weight of the propylene polymer (a), 99 to 1 part by weight of the olefin type elastomer (b), [the total amount of components (a) and (b) being 100 parts by weight], 1 to 20 parts by weight of the olefin polymer (c-1) and 0.01 to 10 parts by weight of the amino compound (c-2). In order to prepare the first or second propylene polymer composition according to the invention (hereinafter sometimes referred to simply as "propylene polymer composition"), the above-mentioned components are homogeneously mixed so that the amounts of each components are within the above-defined ranges, using a mixing method which is carried out in the field of conventional propylene polymers. In this mixing, all the components may be mixed at the same time. Further, it is also possible that some are premixed to prepare a so-called "master batch", and the master batch is mixed with the remaining components. In the preparation of the propylene polymer compositions according to the invention, an organotin compound and/or a tertiary amino compound may be further added. The organotin compound and the tertiary amino compound each play a roll as a catalyst in the reaction of a hydroxyl group of a polyol with an isocyanate to produce urethane bonds. The organotin compound employable for the invention is generally represented by the formula: R 1 -SnX 1 Y 1 Y 2 wherein R 1 is an alkyl group of 4 to 10 carbon atoms, X 1 is an alkyl group of 4 to 10 carbon atoms, a chlorine atom or a hydroxyl group, and Y 1 and Y 2 , which may be the same or different from each other, are each a chlorine atom, -OCOR 2 (wherein R 2 is an alkyl group, an aryl group or an allylalkyl group) or a hydroxyl group. Examples of organotin compound include n-C 4 H 9 Sn(OH) 2 Cl, n-C 4 H 9 Sn(OH)Cl 2 , n-C 4 H 9 SnCl 3 , C 8 H 17 SN(OH) 2 Cl, C 8 H 17 SnCl 3 , (OH) Cl 2 , C 8 H 17 Sn(OH)Cl 2 , n-C 4 H 9 Sn n-C 4 H 9 Sn(OH) 2 OCOC 7 H 15 , n-C 4 H 9 Sn(OH) 2 OCOC 11 H 23 , n-C 8 H 17 Sn(OH) 2 OCOC 7 H 15 , n-C 8 H 17 Sn(OH) 2 OCOC 11 H 23 , n-C 4 H 9 Sn(OCOC 7 H 15 ) 3 , (n-C 4 H 9 ) 2 Sn(OCOC 11 H 23 ) 2 , (n-C 8 H 17 ) 2 Sn(OCOC 11 H 23 ) 2 , (n-C 4 H 9 ) 2 Sn (OCOCH=CHCOOCH 3 ) 2 and (n-C 4 H 9 )Sn(OCOCH=CHCOOCH 2 Ph) 2 . Of these, preferred are n-C 4 H 9 SnCl 3 , (n-C 4 H 9 ) 2 Sn (OCOC 11 H 23 ) 2 and (n-C 8 H 17 ) 2 Sn (OCOC 11 H 23 ) 2 . The organotin compound is used in an amount of 0.01 to 5 % by weight, preferably 0.05 to 3 % by weight, based on the total weight of the propylene polymer (a) and the olefinic elastomer (b). Examples of the tertiary amino compound employable for the invention include dimethylpropylamine, diethylpropylamine, tris (dimethylaminomethyl)phenol, tetraguanidine, N,N-dibutylethanolamine, N-methyl-N,N-diethanolamine, 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo [5.4.0]-7-undecene and tetramethylbutanediamine. The tertiary amino compound is used in an amount of 0.01 to 5 % by weight, preferably 0.05 to 3 % by weight, based on the total weight of the propylene polymer (a) and the olefinic elastomer (b). The propylene polymer compositions of the present invention containing the above-mentioned organotin compound or tertiary amino compound have an extremely high adhesion of coatings because those compounds function as catalysts in the curing reaction between the polyol of the urethane resin and the isocyanate compound. The propylene polymer compositions according to the invention may contain, if necessary, various additives such as other thermoplastic resins, softening agents, fillers, pigments, stabilizers, plasticizers, flame retardants, lubricants, antistatic agents and electrical property improvers, as far as the physical properties and the adhesion of coatings of the propylene polymer compositions of the invention are not deteriorated. Examples of the other thermoplastic resins which may be added include high-density polyethylene, medium-density polyethylene, high-pressure low-density polyethylene, linear low-density polyethylene, poly-1-butene, propylene/1-butene copolymer, styrene/butadiene(/styrene) block copolymer and its hydrogenation product, and styrene/isoprene(/styrene) block copolymer and its hydrogenation product. The softening agents employable for the invention are, for example, mineral oil softening agents. The mineral oil softening agents are high-boiling petroleum fractions which are used for the purpose of weakening the intermolecular action of the olefinic elastomer to facilitate the processing, increasing the dispersibility of the optionally added fillers such as carbon black and white carbon, or lowering rigidity of a vulcanized rubber to improve flexibility or elasticity. These mineral oil softening agents are classified into paraffinic type, naphthenic type and aromatic type. Examples of the fillers employable for the invention include light calcium carbonate, heavy calcium carbonate, basic calcium carbonate, aluminium hydroxide, magnesium hydroxide, magnesium oxide, kaolin, clay, pyrophylite, sericite, talc, calcium silicate, (wollastonite, xonotlite, petal-like calcium silicate), diatomaceous earth, aluminum silicate, silicic anhydride, hydrous silicic acid, mica, magnesium silicate (asbestos, PFM (Processed Mineral Fiber), sepiolite), potassium titanate, elestadite, gypsum fiber, glass balloon, silica balloon, fly ash balloon, shirasu balloon, carbonaceous balloon, organic type balloon (e.g., phenol resin, urea resin, styrene resin, saran resin), silica, alumina, barium sulfate, aluminium sulfate, calcium sulfate, magnesium sulfate, molybdenum disulfide, graphite, glass fiber (e.g., chopped strand, roving, milled glass fiber, glass flake), cut fiber, rock fiber, micro fiber, carbon fiber, aromatic polyamide fiber, potassium titanate fiber, coumarone-indene resin and petroleum resin. Examples of the colorants employable for the invention include carbon black, titanium oxide, zinc white, red iron oxide, ultramarine, Prussian blue, azo pigments, nitroso pigments, lake pigments and phthalocyanine pigments. To the propylene polymer compositions of the present invention, there can be added conventionally known heat stabilizers such as those of the phenol type, sulfite type, phenylalkane type, phosphite type and amine type, aging inhibitors, weathering stabilizers, antistatic agents, and lubricants such as metallic soap and wax, in such amounts as generally used for olefin plastics or olefin copolymer rubbers. The propylene polymer compositions according to the invention are prepared by melt-kneading each of the above-described components. As the kneading apparatus, a mixing roll, an intensive mixer (e.g., Banbury mixer, kneader), a single-screw extruder or a twin-screw extruder can be employed, and the kneading apparatus desirably is of the non-open type. The kneading is usually carried out at a temperature of 150 to 280 °C, preferably 170 to 240 °C, usually for a period of 1 to 20 minutes, preferably 1 to 10 minutes. In general, the compositions thus obtained are granulated into pellets and the pellets are molded into the desired products by molding methods which are generally conducted in the thermoplastic resin field, for example by injection molding, extrusion molding and calendering. The molded products obtained from the propylene polymer compositions of the invention have excellent adhesion of coatings such as urethane resin coatings and amino resin coatings. The urethane resin coatings are those which generally form a coating film by a reaction of a polyisocyanate with a polyol compound, and they include two types, i.e., a one-pack type and a two-pack type. Further, there is a powdery coating using a block type isocyanate in the urethane resin coatings. The molded products obtained from the propylene polymer compositions of the invention have a good affinity for any of these urethane resin coatings. The amino resin coatings include melamine resin coatings, benzoguanamine resin coatings and urea resin coatings. These coatings are those which form a coating film by a process comprising reacting a starting material having an amino group with formaldehyde to produce a monomer having high reactivity, then subjecting the monomer to addition condensation to produce a methylol group and reacting the methylol group with a hydroxyl group of an alcohol. These coatings may be used by mixing them with an oil-modified alkyd resin having plasticity, an oil-free alkyd resin, an oil vanish, an acrylic resin or an epoxy ester resin. Described below is one example of a coating method using, for example, a urethane resin coating. A molded product formed from the propylene polymer composition of the present invention is subjected to washing with water and cleaning with an ordinary industrial detergent, each at least once, then further washed with water and heated to dryness. That is, when the molded product obtained from the propylene polymer composition of the invention is to be coated, a conventionally used cleaning treatment (surface treatment) using vapors of a chlorine type solvent is not always necessary. The thus dried molded product is coated with the urethane resin coating, then if necessary heated, to form an urethane resin coating film. The thus formed coating film has extremely high adhesion properties to the molded product, even though no cleaning treatment with vapors of a chlorine solvent has been carried out. The first propylene polymer composition according to the present invention comprises the propylene polymer, the olefinic elastomer and the specific polar group-containing olefin polymer, in a specific amount, and hence has an excellent adhesion of coatings such as urethane resin coatings and amino resin coatings. The second propylene polymer composition according to the present invention comprises the propylene polymer, the olefinic elastomer, the olefin polymer containing a carboxyl group or an acid anhydride group and the amino compound, in a specific amount, and hence has an excellent adhesion of coatings such as urethane resin coatings and amino resin coatings. Further, the propylene polymer compositions of the present invention as described above have excellent moldability, so that they can be molded by apparatuses which are used for conventional thermoplastics. They are suitable for, for example, extrusion molding, calendering and injection molding. Utilizing the above-mentioned properties, the propylene polymer compositions of the invention can be widely used for parts or materials to be coated with coatings, for example, automotive parts, motorcycle parts, electrical apparatus parts, daily necessities, civil engineering and construction materials, general industrial materials, office and information machines, packaging materials, sporting goods and medical appliances. The present invention will now be further described in the following Examples. The physical properties of the propylene polymer compositions used in the following Examples and Comparative Examples are measured as follows. (1) Flexural modulus (FM) The flexural modulus was measured in accordance with ASTM D 790 using a specimen having a thickness of 1/8 inch (0.3cm). (2) Coating test The coating tests of Examples 1 - 28 and 31 - 47 and Comparative Examples 1 - 6 and 9 - 11 are carried out as follows. Preparation of a specimen A square plate formed by a 50-ton (50.8 x 10 3 kg) injection molding machine was coated with the following coating. Prior to the coating, the surface of the square plate was wiped with a cloth impregnated with isopropanol. Coating (a) The square plate was coated with a two-pack urethane resin coating (trade name: R-271, available from Nippon B Chemical K.K.) by an air gun so that the thickness of the coating film was 60 µm on a dry basis. Baking was carried out at 100 °C for 30 minutes. (b) The square plate was coated with a melamine resin coating (trade name: Flexene #105, available from Nippon B Chemical K.K.) by an air gun so that the thickness of the coating film was 60 µm on a dry basis. Baking was carried out at 120 °C for 30 minutes. Cross-cut adhesion test The adhesion properties were evaluated in accordance with a cross-cut adhesion test described in JIS K 5400. That is, a specimen provided with cross-cuts (i.e., a checkered pattern) was prepared, and to the specimen was attached Cellotape (trade name, available from Nichiban Co., Ltd.). Then, the Cellotape was swiftly pulled in a direction of 90° to peel the tape off from the specimen. The number of the coating checkers remaining on the square plate was counted, and the number was taken as an index of the adhesion properties. Peel strength test On a substrate was formed a coating film, and cuts were made at intervals of 1 cm on the coating film by a cutter blade until the blade reached the substrate. Then, the edge of the coating film was peeled off from the substrate, followed by pulling the thus peeled edge in a direction of 180° at a rate of 50 mm/min until the coating film was peeled off from the substrate, so as to measure the peel strength. Reference Example 1 [Preparation of a modified propylene polymer (1)] 50 g of a propylene homopolymer (MFR: 10 g/10 min (ASTM D 1238, 230 °C, load of 2.16 kg)) and 500 ml of p-xylene were introduced into a 1-liter glass separable flask and heated to 130 °C to dissolve the propylene homopolymer in the p-xylene. Then, to the resultant solution were dropwise added 5 g of maleic anhydride and 0.5 g of dicumyl peroxide over a period of 4 hours, followed by further heating for another 2 hours. Thereafter, the solution was allowed to stand for cooling and then introduced into acetone to obtain a propylene homopolymer graft-modified with maleic anhydride (i.e., the aforesaid component (c-1), hereinafter called "GPP-1" for short). The graft amount of maleic anhydride in GPP-1 was 3.0 % by weight when measured by infrared absorption spectral analysis. The intrinsic viscosity [η] of GPP-1 as measured in decalin at 135 °C was 0.38 dl/g. Reference Example 2 [Heating of a mixture of the modified propylene polymer (1) and an amino compound] 50 g of GPP-1 obtained in Reference Example 1, 3 g of 2-aminoethanol and 500 ml of p-xylene were introduced into a 1-liter glass separable flask and heated to 140 °C for 3 hours with stirring. The molar ratio between the acid anhydride group derived from the maleic anhydride in GPP-1 and 2-aminoethanol thus introduced into the reaction system was 1 : 3.2. Then, the contents of the flask were allowed to stand for cooling and introduced into 3 liters of acetone to separate a precipitate by filtration. The precipitate was further subjected to washing with 2 liters of acetone and filtration three times, respectively. The resultant precipitate was vacuum dried to obtain a polar group-containing propylene polymer (i.e., the aforesaid component (c), hereinafter called "MPP-1" for short). The reaction ratio of the acid anhydride group calculated by the nitrogen atom content determined by elemental analysis of MPP-1 was 90 %. The intrinsic viscosity [η] of MPP-1 as measured in decalin at 135 °C was 0.35 dl/g. Reference Example 3 [Preparation of a modified propylene polymer (2)] 1,000 g of a propylene/ethylene random copolymer (MFR: 40 g/10 min (ASTM D 1238, 230 °C, load of 2.16 kg), ethylene content: 2 % by mol) was introduced into a 5-liter reaction vessel and heated to 380 °C, followed by stirring at the same temperature for 1 hour to perform a heat degradation. After the thus degraded product was allowed to stand for cooling, it was ground so that the resultant particles passed through a sieve of 20-in mesh. The intrinsic viscosity [η] of the obtained propylene/ethylene random copolymer (hereinafter called "DPP-1" for short) as measured in decalin at 135 °C was 0.30 dl/g. 300 g of DPP-1 was introduced into a 1-liter glass separable flask, and the system was purged with nitrogen. Subsequently, the DPP-1 was heated to 170 °C to melt it, and then to the system were dropwise added 15 g of maleic anhydride and 3.5 g of di-t-butyl peroxide over a period of 5 hours. The melted DPP-1 was further heated for 2 hours, then the pressure in the system was reduced, and the system was deaerated at a pressure of 5 mmHg (0.7 kPa) for 1 hour. After the deaeration, the system was cooled to 160 °C to obtain a modified propylene polymer (i.e., the aforesaid component (c-1), hereinafter called "GPP-2" for short). The graft amount of maleic anhydride in GPP-2 was 4.5 % by weight when measured by infrared absorption spectral analysis. The intrinsic viscosity [η] of GPP-2 as measured in decalin at 135 °C was 0.35 dl/g. Reference Example 4 [Heating of a mixture of the modified propylene polymer (1) and an amino compound] 300 g of the GPP-1 obtained in Reference Example 1 and 30 g of N-aminoethylethanolamine were introduced into a 1-liter glass separable flask and then heated to 170 °C to melt them. The molar ratio between the acid anhydride group derived from the maleic anhydride in GPP-1 and N-aminoethylethanolamine thus introduced into the reaction system was 1 : 2.1. Subsequently, the contents of the flask were heated for 4 hours with stirring, and then the system was kept at a pressure of 5 mmHg (0.7 kPa) for 1 hour to remove the unreacted N-aminoethylethanolamine. Then, the contents of the flask were allowed to stand for cooling to obtain a polar group-containing propylene polymer (i.e., the aforesaid component (c), hereinafter called "MPP-2" for short). The reaction ratio of the acid anhydride group calculated by the nitrogen atom content determined by elemental analysis of the obtained MPP-2 was 85 %. The intrinsic viscosity [η] of MPP-2 as measured in decalin at 135 °C was 0.38 dl/g. Reference Example 5 [Preparation of a modified propylene polymer (3)] A 1-liter stainless steel autoclave equipped with a helical type stirrer having a double helical ribbon was charged with 100 g of the DPP-1 (the degraded propylene/ethylene random copolymer) obtained in Reference Example 3, and the system was completely purged with nitrogen. Subsequently, a solution consisting of 2 g of maleic anhydride, 0.8 g of benzoyl peroxide and 15 ml of toluene was dropwise added to the DPP-1 over a period of 10 minutes while stirring the DPP-1 at room temperature. After the addition, the resultant mixture was further stirred for 30 minutes at room temperature. Then, the temperature of the system was set to 100 °C, followed by heating at the same temperature for 4 hours to obtain a modified product. The modified product thus obtained was dissolved in p-xylene at 130 °C, and the resultant solution was subjected to re-precipitation purification by the use of acetone as a poor solvent, to obtain a modified propylene/ethylene random copolymer (i.e., the aforesaid component (c-1), hereinafter called "GPP-3" for short). The graft amount of maleic anhydride in the obtained GPP-3 was 1.2 % by weight when measured by means of infrared absorption spectral analysis. The intrinsic viscosity [η] of GPP-3 as measured in decalin at 135 °C was 0.45 dl/g. Reference Example 6 [Heating of a mixture of the modified propylene polymer (3) and an amino compound] A 1-liter stainless steel autoclave equipped with a helical type stirrer having a double helical ribbon was charged with 100 g of the GPP-3 obtained in Reference Example 5 and 10 g of 2-(2-aminoethoxy)ethanol. The molar ratio between the acid anhydride group derived from the maleic anhydride in GPP-3 and 2-(2-aminoethoxy)ethanol thus introduced into the reaction system was 1 : 8. Subsequently, the contents of the autoclave were heated for 4 hours with stirring, and then the system was kept at a pressure of 5 mmHg (0.7 kPa) for 1 hour to remove the unreacted 2-(2-aminoethoxy)ethanol. Then, the contents of the autoclave were allowed to stand for cooling to obtain a polar group-containing propylene polymer (i.e., the aforesaid component (c), hereinafter called "MPP-3" for short). The reaction ratio of the acid anhydride group calculated by the nitrogen atom content determined by elemental analysis of the obtained MPP-3 was 80 %. The intrinsic viscosity [η] of MPP-3 as measured in decalin at 135 °C was 0.48 dl/g. Reference Example 7 [Preparation of a modified propylene polymer (4)] 100 parts by weight of a propylene homopolymer (MFR: 0.4 g/10 min (ASTM D 1238, 230 °C, load of 2.16 kg)), 1.5 parts by weight of maleic anhydride and 0.08 parts by weight of 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3 were mixed in a Henschel mixer at room temperature. Then, the resultant mixture was melt-kneaded by a twin-screw vented extruder (screw diameter: 30 mm, L/D = 30) at a cylinder preset temperature of 200 °C, and then granulated. The pellets obtained as above were dissolved in p-xylene at 130 °C, and the resultant solution was subjected to re-precipitation purification by the use of acetone as a poor solvent, to obtain a modified propylene homopolymer (i.e., the aforesaid component (c-1), hereinafter called "GPP-4" for short). The graft amount of maleic anhydride in the obtained GPP-4 was 0.2 % by weight when measured by infrared absorption spectral analysis. The MFR (ASTM D 1238, 230 °C, load of 2.16 kg) of GPP-4 was 45 g/10 min, and the intrinsic viscosity [η] thereof as measured in decalin at 135 °C was 1.50 dl/g. Reference Example 8 [Heating of a mixture of the modified propylene polymer (4) and an amino compound] 100 parts by weight of the GPP-4 obtained in Reference Example 7 and 5 parts by weight of 2-(2-aminoethoxy)ethanol were mixed in a Henschel mixer. The molar ratio between the acid anhydride group derived from maleic anhydride in GPP-4 and the 2-(2-aminoethoxy)ethanol thus introduced into the reaction system was 1 : 10. Then, the resultant mixture was melt-kneaded by a twin-screw vented extruder (screw diameter: 30 mm, L/D = 30) at a cylinder preset temperature of 200 °C, to obtain a polar group-containing propylene polymer (i.e., the aforesaid component (c), hereinafter called "MPP-4" for short). The reaction ratio of the acid anhydride group calculated by the nitrogen atom content determined by elemental analysis of the obtained MPP-4 was 87 %. The intrinsic viscosity [η] of MPP-4 as measured in decalin at 135 °C was 0.48 dl/g. Reference Example 9 [Preparation of a modified propylene polymer (5)] A 1-liter stainless steel autoclave equipped with a helical type stirrer having a double helical ribbon was charged with 100 g of a propylene homopolymer (MFR: 45 g/10 min (ASTM D 1238, 230 °C, load of 2.16 kg), mean particle diameter: 0.8 mm), and the system was completely purged with nitrogen. Subsequently, a solution consisting of 5 g of an acrylic acid, 0.2 g of benzoyl peroxide and 10 ml of toluene was dropwise added to the propylene homopolymer over a period of 10 minutes while stirring the propylene homopolymer at room temperature. After the addition, the resultant mixture was further stirred for 30 minutes at room temperature. Then, the temperature of the system was set to 100 °C, followed by heating at the same temperature for 4 hours to obtain a modified product. The modified product thus obtained was dissolved in p-xylene at 130 °C, and the resultant solution was subjected to re-precipitation purification by the use of acetone as a poor solvent, to obtain a modified propylene homopolymer (i.e., the aforesaid component (c-1), hereinafter called "GPP-5" for short). The graft amount of the acrylic acid in the obtained GPP-5 was 4.2 % by weight when measured by infrared absorption spectral analysis. The intrinsic viscosity [η] of GPP-5 as measured in decalin at 135 °C was 1.10 dl/g. Reference Example 10 [Heating of a mixture of the modified propylene polymer (5) and an amino compound] A 1-liter stainless steel autoclave equipped with a helical type stirrer having a double helical ribbon were charged with 100 g of the GPP-5 obtained in Reference Example 9 and 10 g of 2-aminoethanol. The molar ratio between the carboxyl group derived from the acrylic acid in GPP-5 and the 2-aminoethanol thus introduced into the reaction system was 1 : 3. Subsequently, the contents of the autoclave were heated for 4 hours with stirring, and then the system was kept at a pressure of 5 mmHg (0.7 kPa) for 1 hour to remove the unreacted 2-aminoethanol. Then, the contents of the autoclave were allowed to stand for cooling to obtain a polar group-containing propylene polymer (i.e., the aforesaid component (c), hereinafter called "MPP-5" for short). The reaction ratio of the carboxyl group calculated by the nitrogen atom content determined by elemental analysis of the obtained MPP-5 was 82 %. The intrinsic viscosity [η] of MPP-5 as measured in decalin at 135 °C was 1.10 dl/g. Reference Example 11 [Heating of a mixture of the modified propylene polymer (2) and an amino compound] 300 g of the GPP-2 obtained in Reference Example 3, 3 g of 2-aminoethanol and 500 ml of p-xylene were introduced into a 1-liter glass separable flask and heated for 3 hours with stirring. The molar ratio between the acid anhydride group derived from maleic anhydride in GPP-2 and the 2-aminoethanol thus introduced into the reaction system was 1 : 1. Subsequently, the contents of the flask were allowed to stand for cooling and then introduced into acetone, to obtain a polar group-containing propylene polymer (i.e., the aforesaid component (c), hereinafter called "MPP-6" for short). The reaction ratio of the acid anhydride group calculated by the nitrogen atom content determined by elemental analysis of the obtained MPP-6 was 80 %. The intrinsic viscosity [η] of MPP-6 as measured in decalin at 135 °C was 0.32 dl/g. Reference Example 12 [Heating of a mixture of the modified propylene polymer (2) and an amino compound] A 1-liter stainless steel autoclave equipped with a helical type stirrer having a double helical ribbon was charged with 100 g of the GPP-2 obtained in Reference Example 3 and 10 g of 2-(2-aminoethoxy)ethanol. The molar ratio between the acid anhydride group derived from maleic anhydride in GPP-2 and the 2-(2-aminoethoxy)ethanol thus introduced into the reaction system was 1 : 2. Subsequently, the contents of the autoclave were heated for 4 hours with stirring, and then the system was kept at a pressure of 5 mmHg (0.7 kPa) for 1 hour to remove the unreacted 2-(2-aminoethoxy)ethanol. Then, the contents of the autoclave were allowed to stand for cooling to obtain a polar group-containing propylene polymer (i.e., the aforesaid component (c), hereinafter called "MPP-7" for short). The reaction ratio of the acid anhydride group calculated by the nitrogen atom content determined by elemental analysis of the obtained MPP-7 was 85 %. The intrinsic viscosity [η] of MPP-7 as measured in decalin at 135 °C was 0.28 dl/g. Reference Example 13 [Heating of a mixture of the modified propylene polymer(5) and an amino compound] 300 g of the GPP-5 obtained in Reference Example 9, 3 g of 2-aminoethanol and 500 ml of p-xylene were introduced into a 1-liter glass separable flask. The molar ratio between the carboxyl group derived from the acrylic acid in GPP-5 and the 2-aminoethanol thus introduced into the reaction system was 1 : 1. Subsequently, the contents of the flask were heated for 3 hours with stirring, then allowed to stand for cooling and introduced into 3 liters of acetone to separate a precipitate by filtration. The precipitate was further subjected to washing with 2 liters of acetone and filtration three times, respectively. The resultant precipitate was vacuum dried to obtain a polar group-containing propylene polymer (i.e., the aforesaid component (c), hereinafter called "MPP-8" for short). The reaction ratio of the carboxyl group calculated by the nitrogen atom content determined by elemental analysis of the obtained MPP-8 was 80 %. The intrinsic viscosity [η] of MPP-8 as measured in decalin at 135 °C was 1.05 dl/g. Reference Example 14 [Heating of a mixture of the modified propylene polymer (4) and an amino compound] 50 g of the GPP-4 obtained in Reference Example 7, 2 g of N-aminoethylethanolamine and 500 ml of p-xylene were introduced into a 1-liter glass separable flask and heated at 140 °C for 3 hours. Thereafter, the contents of the flask were allowed to stand for cooling and then introduced into acetone to obtain a modified propylene polymer (hereinafter called "MPP-9" for short). The molar ratio between the acid anhydride group derived from maleic anhydride in GPP-4 and the N-aminoethylethanolamine thus introduced into the reaction system was 1 : 3. The reaction ratio of the acid anhydride group calculated by the nitrogen atom content determined by elemental analysis of the obtained MPP-9 was 85 %. The intrinsic viscosity [η] of the MPP-9 as measured in decalin at 135 °C was 1.40 dl/g. Examples 1- 28 The components shown in Table 1 were melt-kneaded by a twin-screw vented extruder (screw diameter: 30 mm, L/D = 42) at a cylinder preset temperature of 200 °C to prepare a propylene polymer composition. This composition was molded into a square plate by an injection molding machine to obtain a specimen for the aforesaid flexural test and coating test, and those tests were carried out. The results are set forth in Table 1. Details of each components shown in Tables 1, 2 and 3 are as follows. Propylene polymer (a) (1) Propylene homopolymer (hereinafter called "PP-1" for short) MFR (ASTM D 1238, 230 °C, load of 2.16 kg): 20 g/10 min Density: 0.91 g/cm 3 (2) Propylene/ethylene block copolymer (hereinafter called "PP-2" for short) MFR (ASTM D 1238, 230 °C, load of 2.16 kg): 14 g/10 min Ethylene content: 12 % by mol Density: 0.91 g/cm 3 (3) Propylene/ethylene copolymer (hereinafter called "PP-3" for short) MFR (ASTM D 1238, 230 °C, load of 2.16 kg): 40 g/10 min Ethylene content: 10 % by mol Density: 0.91 g/cm 3 (4) Propylene/ethylene block copolymer (hereinafter called "PP-4" for short) MFR (ASTM D 1238, 230 °C, load of 2.16 kg) : 40 g/10 min Ethylene content: 12 % by mol Density: 0.91 g/cm 3 Olefin type elastomer (b) (1) Ethylene/propylene copolymer rubber (hereinafter called "EPR" for short) MFR (ASTM D 1238, 230 °C, load or 2.16 kg): 0.7 g/10 min Ethylene content: 81 % by mol Density: 0.87 g/cm 3 (2) Ethylene/1-butene copolymer rubber (hereinafter called "EBR" for short) MFR (ASTM D 1238, 230 °C, load of 2.16 kg): 0.5 g/10 min Ethylene content: 50 % by mol Density: 0.88 g/cm 3 Amino compound (c-2) (1) 2-aminoethanol (H 2 NCH 2 CH 2 OH, hereinafter called "A-1" for short) (2) 2-(2-aminoethoxy)ethanol (H 2 NCH 2 CH 2 OCH 2 CH 2 OH, hereinafter called "A-2" for short) (3) N-aminoethylethanolamine (H 2 NC 2 H 4 NHC 2 H 4 OH, hereinafter called "A-3" for short) Thermoplastic resin other than the above components (1) Linear low-density polyethylene (hereinafter called "LLDPE" for short) Comonomer: 1-butene 1-Butene content: 2 % by mol MFR (ASTM D 1238, 230 °C, load of 2.16 kg): 25 g/10 min Density: 0.92 g/cm 3 (2) Styrene/butadiene/styrene block copolymer hydrogenation product (hereinafter called "SEBS" for short) Styrene content: 30 % by weight MFR (ASTM D 1238, 230 °C, load of 2.16 kg): 4 g/10 min Organotin compound (1) Dibutyl tin dilaurate (hereinafter called "DBTDL" for short) Tertiary amino compound (1) 1,4-Diazabicyclo[2.2.2]octane (hereinafter called "DABCO" for short) Filler (1) Talc (2) Magnesium sulfate Comparative Example 1 Similarly to Example 1, the above PP-1 was molded into a square plate by an injection molding machine to obtain a specimen for the flexural test and the coating test, and the tests were carried out. The results are set forth in Table 1 Comparative Example 2 Similarly to Example 1, the above EPR was molded into a square plate by an injection molding machine to obtain a specimen for the flexural test and the coating test, and the tests were carried out. The results are set forth in Table 1. Comparative Examples 3 - 6 The components shown in Table 1 were melt-kneaded by a twin-screw vented extruder (screw diameter: 30 mm, L/D = 42) at a cylinder preset temperature of 200 °C to prepare a propylene polymer composition. This composition was molded into a square plate by an injection molding machine to obtain a specimen for the aforesaid flexural test and coating test, and those tests were carried out. The results are set forth in Table 1. Examples 29 & 30 Comparative Examples 7 & 8 The components shown in Table 2 were mixed with each other, and the resultant mixture was kneaded and granulated by a twin-screw kneading extruder (BT-30 type, produced by Plastic Kogakusha K.K.) at 200 °C to obtain pellets. Then, the pellets were injection molded into a square plate (12 mm × 13 mm × 2 mm (thickness)) for a coating test by a screw in-line type injection molding machine (Toshiba Co., Ltd.) at 200 °C, and the following coating test was carried out. [Coating test method] A two-pack type urethane resin coating (trade name: R-271, available from Nippon B Chemical K.K.) was prepared. In the preparation of a specimen for a cross-cut adhesion test, the square plate was spray-coated with the urethane resin coating by means of an air gun so that the thickness of the coating film was about 40 µm. Further, in the preparation of a specimen for a peel strength test, the square plate was spray-coated with the same coating by means of an air gun so that the thickness of the coating film was about 100 µm. Thereafter, each of the specimens was baked at 85 °C for 30 minutes to cure the coating. After completion of the baking, the specimens were allowed to stand for 72 hours at room temperature, and then subjected to the following cross-cut adhesion test and peel strength test. The results are set forth in Table 2 Cross-cut adhesion test On the surface of the specimen, cuts of 11 lines parallel to each other were made at intervals of 2 mm in the longitudinal direction and in the crosswise direction (those directions being at right angles), respectively, by the use of a single-edged razor to form 100 checkers, on which a cellophane adhesive tape (JIS-Z-1522) was firmly bonded. Then, the adhesive tape was peeled off at one stroke from the coating film surface while keeping the angle between the adhesive tape and the coating film surface at about 30°. The state of the checkers was observed and the number of the checkers having the coating film thereon was counted. Peel strength test On the surface of the coating film (thickness: 100 µm) of the specimen, linear cuts were made at intervals of 1 cm by the use of a single-edged razor. The belt-like portion of the coating film was pulled in the direction of 180° at a rate of 50 mm/min by means of a tensile tester, and a load required for peeling off the belt-like portion from the specimen was measured. The results are set forth in Table 2. Example Comp. Example Composition [Part by weight] 29 30 7 8 Component (a) PP-3 50 45 50 60 Component (b) EPR 40 36 40 40 Component (c) MPP-1 10 9 -- -- Component (c-1) GPP-1 -- -- 10 -- Filler Talc -- 10 -- -- Organotin compound DBTDL 0.2 0.2 0.2 0.2 Adhesion of coating Cross-cut adhesion test 100 100 10 0 Urethane resin coating Peel strength test 1200 1100 100 10 Examples 31 - 47, Comparative Examples 9 - 11 The components shown in Table 3 were melt-kneaded by a twin-screw vented extruder (screw diameter: 30 mm, L/D = 42) at a cylinder preset temperature of 200 °C to a prepare propylene polymer composition. This composition was molded into a square plate by an injection molding machine to obtain a specimen for the aforesaid flexural test or coating test, and those tests were carried out. The results are set forth in Table 3.

Claims: A propylene polymer composition comprising: (a) a propylene polymer in an amount of 1 to 99 parts by weight, (b) an olefinic elastomer having a Mooney viscosity ML 1+4 (100°C) of 10 to 150 in an amount of 99 to 1 parts by weight, the total amount of components (a) and (b) being 100 parts by weight, and (c) a polar group-containing olefin polymer in an amount from 1 to 30% by weight based on the total weight of components (a) and (b), said polymer (c) being obtainable by heating (c-1) an olefin polymer comprising carboxyl and/or an acid anhydride groups and (c-2) an amino compound. A composition according to claim 1, wherein the olefin polymer (c-1) is a propylene polymer or propylene/ethylene random copolymer having an ethylene content of 1 to 5% by mol comprising carboxyl and/or acid anhydride groups. A composition according to claim 2 wherein the olefin polymer (c-1) is obtainable by grafting one or more unsaturated compounds comprising a carboxyl and/or acid anhydride group, to a propylene homopolymer or propylene/ethylene random copolymer having an ethylene content of 1 to 5% by mol. A composition according to claim 2 or 3, wherein the olefin polymer (c-1) is a propylene/ethylene random copolymer having an ethylene content of 1 to 5% by mol comprising carboxyl and/or acid anhydride groups and having an intrinsic viscosity [η], as measured in decalin at 135°C, from 0.1 to 1.0 dl/g. A composition according to any one of the preceding claims wherein the amino compound (c-2) is 2-aminoethanol, N-aminoethylethanolamine or 2-(2-aminoethoxy)ethanol. A composition according to any one of the preceding claims, which further comprises an organotin compound and/or a tertiary amino compound in an amount of 0.01 to 5% of the total weight of components (a) and (b). A propylene polymer composition comprising: (a) a propylene polymer in an amount of 1 to 99 parts by weight, (b) a olefinic elastomer having a Mooney viscosity ML 1+4 (100°C) of 10 to 150 in an amount of 99 to 1 parts by weight, the total amount of components (a) and (b) being 100 parts by weight, (c-1) an olefin polymer comprising carboxyl and/or acid anhydride groups, in an amount from 1 to 20% of the total weight of components (a) and (b), and (c-2) an amino compound which is capable of reacting with the olefin polymer (c-1) in an amount from 0.01 to 10% of the total weight of components (a) and (b). A composition according to claim 7, wherein the olefin polymer (c-1) is a propylene polymer or a propylene/ethylene random copolymer having an ethylene content of 1 to 5% by mol comprising carboxy and/or acid anhydride groups. A composition according to claim 8 wherein the olefin polymer (c-1) is obtainable by grafting one or more unsaturated compounds comprising a carboxyl and/or acid anhydride group, to a propylene homopolymer or propylene/ethylene random copolymer having an ethylene content of 1 to 5% by mol. A composition according to claim 8 or 9, wherein the olefin polymer (c-1) is a propylene/ethylene random copolymer having an ethylene content of 1 to 5% by mole comprising carboxyl and/or acid anhydride groups and having an intrinsic viscosity [η], as measured in decalin at 135°C, of not more than 1 dl/g. A composition according to any one of claims 7 to 10 wherein the amino compound (c-2) is 2-aminoethanol, N-aminoethylethanol or 2-(2-aminoethoxy)ethanol.

Inventors: HASHIMOTO MIKIO, HIRAOKA SHOJI, INAGAKI HAJIME, YAMAGUCHI MASAYOSHI, HASHIMOTO, MIKIO, HIRAOKA, SHOJI, INAGAKI, HAJIME, YAMAGUCHI, MASAYOSHI, HASHIMOTO, MIKIO, C/O MITSUI PETROCHEM. IND. LTD., HIRAOKA, SHOJI, C/O MITSUI PETROCHEM. IND. LTD., INAGAKI, HAJIME, C/O MITSUI PETROCHEM. IND. LTD., YAMAGUCHI, MASAYOSHI, C/O MITSUI PETROCHEM. IND.
Applicants: MITSUI PETROCHEMICAL IND, MITSUI PETROCHEMICAL INDUSTRIES, LTD.
Application year: 1994
Main classification: C08L23
IPC codes: C08L23, C08K5